The present invention relates to solar energy concentration.
U.S. Pat. No. 4,046,462 and NASA Tech Briefs, Spring, 1979, pages 44 and 45, both disclosed a solar concentrator with a flexible, reflective surface. In order to adjust the curvature of this reflective surface, a non-uniform differential pressure was applied to the reflective surface. The differential pressure was made non-uniform by either making the thickness of a membrane on which the reflective surface was mounted non-uniform by spraying a dissolved plastic on certain portions of the membrane to make the membrane non-uniform in thickness or by application of localized electrostatic or magnetic pressure to the membrane. Other patents, such as U.S. Pat. Nos. 4,134,387 and 4,056,309 utilized flexible, reflective surfaces, but supported them with rigid surfaces so that their curvature could be adjusted only by changing support surfaces.
Other solar concentrators known to the inventor of general interest but, so far as is known, not using flexible reflective surfaces were U.S. Pat. Nos. 3,905,352, 4,038,971, 4,056,313, 4,110,010, 4,131,336, 4,137,897, 4,148,564, 4,153,039, 4,158,356, 4,159,710.
Other publications relating to solar energy in general known to applicant are:
"Proceedings," Solar Energy Conference, C. S. Taylor;
"Applied Solar Energy: An Introduction," A. B. Meinel and M. P. Meinel;
"A 2.7 Meter Diameter Vacuum Film Solar Concentrator," Applied Solar Energy, S. V. Stardobtsev, G. Ya. Umarov and N. V. Kordub, Volume 1, No. 1, Jan.-Feb. 1965, pp. 16-18;
"Experimental Investigation of Certain Properties of Parabolic Cylindrical Inflatable Film Concentrators," G Ya. Umarov, Z. Dzhalolv, and A. Abduazizov, Applied Solar Energy, Volume 4, No. 5, 1968, pp. 27-29;
Appl. Opt., W. G. Steward and F. Kreith, 14, No. 7, p. 1509;
Tech. Rept., Gulf General Atomics Corp., J. L. Russel (1974);
"Analysis of a Flat Mirror Solar Concentrator," R. K . Collier and G. K. Matthew, ASME, 76-WA/HT-11 (1976).